An invention known as a non-contact hydrostatic sealing device is, for example, a sealing device that supplies sealing gas between relative sliding faces of a pair of sliding components to seal between the relative sliding faces in a non-contact state, which includes a first seal ring disposed between the high-pressure fluid side and the low-pressure fluid side and having dynamic pressure generation grooves in a first sliding face, one of the sliding faces, a second seal ring having a second sliding face, the other of the sliding faces, which slides relative to the first sliding face, and a sealing gas supply passage that passes through the first sliding face of the first seal ring or the second sliding face of the second seal ring and can communicate with a fluid supply source, in which the dynamic pressure generation grooves in the first sliding face are provided with introduction passages that allow introduction of sealed fluid on the high-pressure side (see Patent Documents 1 and 2, for example).
In the invention of the sealing device described in Patent Documents 1 and 2 above, when sealing gas is supplied between the first sliding face and the second sliding face from the fluid supply source through the sealing gas supply passage, a floating gap of ten-odd micrometers is formed by static pressure generated between the sliding faces, and a sealing gas barrier is formed in the gap, thereby sealing gas in the apparatus. In the event that the sealing gas from the fluid supply source is not supplied between the sliding faces due to an accident or the like, the sealed fluid on the high-pressure side is guided to the dynamic pressure generation grooves in the first sliding face through the introduction passages, and the dynamic pressure generation grooves generate dynamic pressure, producing a gap between the sliding faces, and maintaining a non-contact state between the sliding faces.